The present invention relates broadly to a microwave input stage receiver protector, and in particular to a single stage pre-TR high power/intermediate power stage receiver protector apparatus.
In the present state-of-the-art waveguide receiver protectors for high power radar systems, there are stringent requirements for fast between pulse recovery times. The prior art receiver protector apparatus generally utilized a separate high power capsule stage and capillary stage as the pre-TR and intermediate power stages. The high power pre-TR vial front stage and intermediate power capillary stage use halogen gas fills in order to achieve the fast sub-microsecond recovery times. However, because of their reactive nature, the halogen gases must be enclosed in quartz within these stages. The low power radioactive ignitor stage and diode limiter back stage, reduce leakage power to an acceptable level while not adversely effecting recovery time.
For the lowest firing power and leakage power, either one-quarter or three-quarter wavelength interstage spacing at center band frequency must be used. Since the vial diameter itself is almost one-quarter wavelength at C-band, and is one-quarter wavelength at X-band, three-quarter wavelength spacing must be used between vial and capillary stages at C-band frequencies and higher.
The capillary stage is relatively expensive to build since extremely fine tolerances must be held on both the quartz capillary and its surrounding aluminum fixture. It will be noted that the thin wall quartz tubing of the quartz capillary is the most delicate member in the entire receiver protector. Its breakage results in failure of the receiver protector due to poor recovery time and high leakage power.